Flat insole

ABSTRACT

An insole has an upperside and an underside narrower than the upperside, so as to give an added support, wearing stability, and comfort to the foot.

[0001] This is a continuation-in-part of copending parent application Ser. No. 09/702,661, filed Nov. 1, 2000.

FIELD OF THE INVENTION

[0002] The present invention relates generally to a shoe, and more particularly to an improved flat insole of the shoe.

BACKGROUND OF THE INVENTION

[0003] Conventional shoe insoles normally comprise either flat insoles or flat insoles which are formed to a shape by heating under pressure in a mold. The molded insole affords stability and support to the foot sole in contact with it. However, the molded insole is made at an extra cost and because it is made under pressure, it has a greater rigidity. The rigid molded insole has a lower soothing effect. The process of making the molded insole is costly in view of the fact that the process consumes energy, and that the material cost increases. For example, a flat insole having a thickness of 6 mm is needed to make a modeled insole having a thickness of 4 mm. The flat insole is relatively cost-effective and is made of a foam material which is relatively soft. However, the flat insole is less desirable than the molded insole in terms of stability and support.

[0004] As shown in FIG. 1, the inner wall 71 of a shoe 70 is arcuate. A conventional flat insole 30 is corresponding in size to the shoe sole 71 and is insufficient to cover the foot 100. In addition, the central portion of this insole 30 is prone to cave in from body weight of a person wearing the shoe 70. As a result, the upperside edge 301 of the insole 30 is apt to warp to press against the foot sole.

[0005] As shown in FIGS. 2 and 3, the conventional flat insole 30′ is greater in size than the shoe sole 71 to cover sufficiently the foot 100. However, the upperside edge 301′ tends to press against the foot sole. In addition, the juncture between the flat insole 30′ and the inner wall 72 of the shoe sole 71 tends to have a void, which permits the flat insole 30′ to wrinkle and displace easily. In addition, the insole 30′ can not be securely kept in place in the shoe sole 71.

[0006] Conventional flat insoles are generally devoid an arch to prevent the formation of a void and the pressing of the upperside edge against the foot sole. In light of the formation of a void under the arch, the arch is somewhat suspended, thereby resulting in a great deal of discomfort.

SUMMARY OF THE INVENTION

[0007] The primary objective of the present invention is to provide a flat insole made of foam material and not molded under heat and pressure which is free of the shortcomings of the conventional insoles described above.

[0008] The flat insole of the present invention has an upperside and an underside which is smaller in width than the upperside.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 shows a schematic view of a prior art flat insole in use.

[0010]FIG. 2 shows a schematic view of the prior art flat insole at work.

[0011]FIG. 3 shows a schematic view of another prior art flat insole at work.

[0012]FIG. 4 shows a front view of the present invention.

[0013]FIG. 5 shows a side view of the present invention.

[0014]FIG. 6 shows a schematic view of the present invention at work.

[0015]FIG. 7 shows another schematic view of the present invention at work.

DETAILED DESCRIPTION OF THE INVENTION

[0016] As shown in FIGS. 4 and 5, a flat insole 10 of the present invention is made of a foam material not molded under heat and pressure and is composed of a toe portion 11, a sole portion 12, a heel portion 13, and an arch 121 extending from the sole portion 12. The flat insole 10 has two longitudinal side walls which slant from two upperside edges 101 such that the two longitudinal side walls form respectively angles α and β with an underside of the insole 10. The α angle and the β angle are greater than 90 degrees. As a result, the flat insole 10 has an upperside and an underside which is smaller in width than the upperside. The toe portion has the smallest machining angle. The heel portion 13 has the intermediate machining angle. The arch 121 of the sole portion 12 has the greatest machining angle. The slanted longitudinal side walls of the flat insole 10 have arcuate edges.

[0017] As shown in FIG. 6, the flat insole 10 is kept in place in a shoe 70 such that no void is formed between the heel portion 13 and the inner wall 72 of the shoe 70, and that the upperside edges 101 of the flat insole 10 are in an intimate contact with the inner wall of the shoe 70, thereby preventing the upperside edges 101 from warping to press against the sole of a foot wearing the shoe 70.

[0018] In light of the flat insole 10 of the present invention being provided with the arch 121, the flat insole 10 is capable of covering the foot sole 100. As shown in FIG. 7, the arch 121 is in contact with the inner wall 72 of the shoe to prevent the formation of a large void.

[0019] The flat insole 10 of the present invention is securely kept in place in the shoe such that the flat insole 10 is in an intimate contact with the inner wall 72 of the shoe, so as to prevent the flat insole 10 from displacing or twisting.

[0020] The flat insole of the present invention affords a good support to the foot wearing the shoe, thanks to the arch 121 of the flat insole 10. The arch 121 is in contact with the inner wall 72 of the shoe such that only small void 8 is formed.

[0021] The flat insole 10 makes an intimate contact with the inner wall 72 and has a wider upperside to cover the foot sole 100 without pressing against the foot sole.

[0022] The flat insole 10 of the present invention is free of the drawbacks of the conventional flat insole which is prone to warp to press against the foot sole. The present invention affords its wearer comfort.

[0023] Unlike the conventional flat insole and the conventional molded insole, the flat insole 10 of the present invention has a greater allowance for error. As a result, the flat insole 10 of the present invention fits better into the shoe sole 71.

[0024] The flat insole 10 of the present invention is cost-effective in all respects. 

What is claimed is:
 1. A flat insole for use in a shoe, the flat insole being of foam material not molded under heat or pressure and comprising a toe portion, a sole portion and a heel portion; wherein prior to engagement in the shoe said toe portion, said sole portion and said heel portion have an upperside, and an underside parallel to, and smaller in width than said upperside, and two slanted sides opposite to each other and connecting said upperside and said underside; wherein said slanted sides form an angle with said underside greater than 90 degrees; and wherein after engagement in the shoe said slanted sides form arcuate edges against the shoe projecting up from the upperside of the flat insole.
 2. A method for producing the flat insole according to claim 1 so as to engage a shoe, comprising the steps of: cutting a flat piece of foam material which has not been molded under heat or pressure to have a toe portion, a sole portion and a heel portion forming an initial flat insole wherein an upperside and underside thereof are parallel to each other; cutting the opposite sides of the initial flat insole to form slanting sides connecting the underside to the upperside; wherein said underside of the flat insole is smaller in width than said upperside and said slanted sides and form an angle with said underside greater than 90°; engaging the flat insole in the shoe so that said slanted sides form arcuate edges which abut against the shoe and project up from the upperside of the flat insole.
 3. The flat insole according to claim 1, wherein the flat insole is engaged in the shoe with the slanted sides forming arcuate edges against sides of the shoe projecting up from the upperside of the flat insole. 